1. Field of the Invention
This invention is in the field of pulsed injectors of dry pulverized solids, and more specifically pulsed injectors of dry pulverized char fuel as might be used, for example, in a piston internal combustion engine burning dry pulverized char fuel where combustion is intended to be intermittent and not continuous.
2. Description of the Prior Art
Efforts to burn pulverized coal in diesel engines have been made for many years as discussed in reference A, B, and C and the references referred to therein. Much of the recent efforts have been directed toward using slurries of pulverized coal suspended in liquid hydrocarbon or water, as discussed in references D, E, F, G, H, I. Some past efforts have been directed toward using dry pulverized coal, but these have been generally unsuccessful unless pilot injection of diesel fuel or other ignitable fuel is utilized to initiate the burning of the dry pulverized coal. Additionally, an air blast injector is needed in order to disperse the dry pulverized coal throughout the combustion chamber air mass. Thus, for direct burning of dry pulverized coal, an air compressor is needed to furnish the fuel injector blast air and this reduces the power output and efficiency of the engine. It would thus be of great benefit if a dry pulverized coal injector were available capable of adequately dispersing the pulverized coal into the combustion chamber which required only small quantities of blast air.
Methods for burning non-pulverized char fuels in lump or pellet form in piston type internal combustion engines are described in references J and K.
The term, internal combustion engine mechanism, is used herein and in the claims to mean all those portions of prior art internal combustion engines except the fuel supply and mixing systems and spark ignition system, if used, as described in U.S. Pat. No. 4,412,511 (reference J), column 1, line 65, through column 2, line 45, and also to mean a free piston mechanism as described in U.S. Pat. No. 4,372,256, column 1, line 55 through column 2, line 6 and this material from U.S. Pat. No. 4,412,511 and U.S. Pat. No. 4,372,256, is incorporated herein by reference thereto.
The term "char fuel" is used herein and in the claims to mean any fuel, capable of reacting chemically with oxygen to release chemical energy, whose usual physical state is wholly or largely solid or which leaves behind a solid residue after volatile matter has been evolved as defined further in U.S. Pat. No. 4,372,256, column 7, lines 19 through 53, and this material is incorporated herein by reference thereto.
The term "pulverized char fuel" is used herein and in the claims to mean char fuel particles whose size has been sufficiently reduced by grinding or other means that the particle is suspendable within the air or gas flow being used to disperse it. In effect, the aerodynamic forces acting on the particle during injection at least equal the particle weight for pulverized char fuel. The term "dry pulverized char fuel" is used herein and in the claims to mean pulverized char fuel not in a slurry form with any liquid.
The term "ignitable fuel" is used herein and in the claims to mean any liquid or gaseous fuel which can be spark ignited after being mixed with air or a gas containing appreciable oxygen gas. Gasoline, diesel fuel, natural gas, producer gas, etc., are examples of ignitable fuels.
The term "oxygen" and "oxygen gas" refer to molecular oxygen as O.sub.2 and a gas containing oxygen in appreciable quantities, such as air, is referred to as a gas containing appreciable oxygen whereas a gas, such as producer gas, containing very little oxygen is referred to as a gas essentially free of oxygen even though it may contain appreciable portions of atoms of oxygen combined with carbon and hydrogen.
The term "start of each combustion process" is used herein and in the claims to mean that time at which fuel and air are to be mixed together in a combustion chamber for each pulse of burning where pulsating combustion is being utilized.
Prior Art References:
A. "Solid Fuel Applications to Transportation Engines," R. L. Rentz, T. J. Timbario, and R. A. Renner, ASME Paper 810445, 1981.
B. "Coal Fueled Diesel Engines," F. Robben, SAE Paper 831747, 1983.
C. "The Combustion Characteristics of Coal Slurry Fuels in Diesel Engines: Detailed Measurements and Analysis," L. P. Nelson, M. P. Heap, P. W. Sampson, and W. R. Seeker, ASME Paper 85-DGP-19, 1985.
D. "Performance of Coal Slurry Fuel in a Diesel Engine," K. Tatajah and C. D. Wood, SAE Paper 800329, 1980.
E. "Performance of a Diesel Engine Operating on Raw Coal-Diesel Fuel Slurries," H. P. Marshall, S. M. Bhat, S. T. Mulvaney, J. F. Sevelli, SAE Paper 810253, 1981.
F. "Diesel Engine Injection and Combustion of Slurries of Coal, Charcoal and Coke in Diesel Fuel," T. W. Ryan III, L. G. Dodge, SAE Paper 840119.
G. "A Combustion and Wear Analysis of a Compression-Ignition Engine Using Coal Slurry Fuels," J. M. Clingenpeel, M. D. Gurney, D. B. Eccleston, ASME Paper 84-DGP-8.
H. "A Program to Examine the Uses of Coal Slurry Fuels In Diesel Engines," M. D. Gurney, J. M. Clingenpeel, D. B. Eccleston, ASME Paper 84-DGP-9.
I. U.S. Pat. No. 4,381,745, issued May 3, 1983 to J. C. Firey.
J. U.S. Pat. No. 4,412,511, issued Nov. 1, 1983 to J. C. Firey.
K. U.S. Pat. No. 4,372,256, issued Feb. 8, 1983 to J. C. Firey.